Hi @Julien Anid ,
According to my research and testing, there is currently unable to see the progress of the user viewing the video, we can only see who has viewed the file. You can follow these steps to see who has viewed the file:
1.Go to Site Settings >> Click on “Manage Site Features” under Site Actions
2.Activate the “SharePoint Viewers” feature.
3.Then,you will see the names of the people who have viewed the file.
Besides, the issue of tracking users who completed video and the progress of viewing, I suggest you can mention a feedback on this issue. Many features of our current products are designed and upgraded based on customers’ feedback. With requirements like this increase, the problem may well be released in the future. Thanks for your understanding.
Feedback:
https://feedbackportal.microsoft.com/feedback/
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